English

Presentation length and Simon's conjecture

Geometric Topology 2011-05-19 v3

Abstract

In this paper, we show that any knot group maps onto at most finitely many knot groups. This gives an affirmative answer to a conjecture of J. Simon. We also bound the diameter of a closed hyperbolic 3-manifold linearly in terms of the presentation length of its fundamental group, improving a result of White.

Keywords

Cite

@article{arxiv.1006.5262,
  title  = {Presentation length and Simon's conjecture},
  author = {Ian Agol and Yi Liu},
  journal= {arXiv preprint arXiv:1006.5262},
  year   = {2011}
}

Comments

34 pages, 3 figures, fixed some errors, especially in the proof of Prop. 7.2. Final version to appear in Journal of the American Mathematical Society

R2 v1 2026-06-21T15:41:40.542Z